Lots to unpack there...
You don't say how you created the boot drive, so that might be the first thing to check, but for now I'll assume the Fedora boot drive is valid.
Secondly, you don't say what happens at boot time. ordinarily, the OS will only look for MacOS boot drives. To boot from other media/OSes, you can hold the Option key at power-on to get a list of alternative EFI boot volumes to use.
Even then, that might not work if your system has been configured to not allow booting from internal drives via a firmware passcode/lock. If this is your own personal machine that's not likely to be a problem (or, at least, you would have been the one to lock the boot/firmware in the first place, so are already aware of what's needed). If it's a corporate-owned machine, they may have controls in place to prevent external booting.